JP5922856B1 - Liquid discharge head and recording apparatus using the same - Google Patents

Abstract

In the liquid discharge head, the first pressurizing chamber row 11A is arranged on the other side in the other direction of the sub-manifold 5a extending in one direction, and the second pressurizing chamber row 11B is arranged on the one side in the other direction. The 1 squeezing main body 6Aa and the second squeezing main body 6Ba extend in a direction intersecting with one direction and are arranged alternately in one direction, and the first inflow hole 6Ab is more than the second outflow hole 6Bc. The width of the opening of the first inflow hole 6Ab is larger than the width of the opening of the second outflow hole 6Bc, and the flow path of the second aperture 6B is configured in the same manner. Has been.

Description

  The present invention relates to a liquid discharge head and a recording apparatus using the same.

  Conventionally, as a liquid ejection head, for example, an inkjet head that performs various types of printing by ejecting a liquid onto a recording medium is known. 2. Description of the Related Art As a flow path member having a discharge hole, a pressure chamber, and a common flow path used for a liquid discharge head, a member in which a plurality of metal plates each having a hole or groove to be a flow path is stacked is known. . These metal plates are joined with an adhesive. In the metal plate, in order to prevent the adhesive from flowing into the hole or groove at the time of joining, an escape groove for the adhesive is formed in an annular shape surrounding the periphery of the hole or groove. These annular relief grooves are connected to each other (see, for example, Patent Document 1).

Depending on the arrangement of the flow paths, even if an escape groove as described in Patent Document 1 is arranged around the flow path, the distance between the escape grooves for other flow paths arranged nearby is small. As a result, there is a case where the bonding allowance becomes narrow or there is no room for arranging the escape groove in the first place. In particular, squeezing that is a flow path connecting the pressurizing chamber and the common flow path is densely arranged. For this reason, since the escape groove cannot be arranged so as to surround the periphery, the variation in the flow path characteristics of the squeezed when the shape of the flow path changes due to the inflow of the adhesive increases, and the variation in the discharge characteristics increases. was there.
JP 2006-187967 A

  Accordingly, it is possible to provide a liquid discharge head that can reduce the possibility of an adhesive flowing into a squeeze, and a recording apparatus using the liquid discharge head.

  One aspect of the liquid discharge head is a flow path having a plurality of discharge holes, a plurality of pressurization chambers connected to the plurality of discharge holes, and a common flow path for supplying liquid to the plurality of pressurization chambers. A liquid discharge head including a member and a plurality of pressurizing units that respectively pressurize liquids in the plurality of pressurizing chambers, wherein the channel member has holes or grooves serving as channels. A plurality of plates are stacked, and when the channel member is viewed in plan, the common channel is long in one direction, and the plurality of pressurizing chambers are arranged side by side. However, one row on each side of the common flow path is arranged in a total of two rows in the one direction, one of the two pressure chamber rows being a first pressure chamber row and the other being a second pressure. When the chamber row is used, the pressurizing chamber belonging to the first pressurizing chamber row and the common flow path are connected via a first squeeze. The first squeezing body extending in a direction orthogonal to the stacking direction, and the first squeezing main body and the common flow path on the common flow channel side of the first squeezing main body. A first inflow hole that connects the first squeezing body and the pressurizing chamber in the laminating direction on the pressure chamber side of the first squeezing body. The pressurizing chamber belonging to the second pressurizing chamber row and the common flow path are connected via a second constriction, and the second constriction extends in a direction perpendicular to the stacking direction. A second squeezing main body, a second inflow hole connecting the second squeezing main body and the common flow channel in the stacking direction on the common flow path side of the second squeezing main body, and A second outflow that connects the main body and the pressurizing chamber in the stacking direction on the pressurizing chamber side. The first restriction body and the second restriction body extend in a direction intersecting the one direction, and are alternately arranged in the one direction, and are orthogonal to the one direction. Is the other direction, the first inflow hole is disposed on one side in the other direction with respect to the second outflow hole, and the second inflow hole is in the other direction with respect to the first outflow hole. The width of the opening of the first inflow hole is larger than the width of the opening of the second outflow hole, and the width of the opening of the second inflow hole is the opening of the first outflow hole. Greater than the width of

  One aspect of the recording apparatus includes the liquid discharge head, a transport unit that transports a recording medium to the liquid discharge head, and a control unit that controls the liquid discharge head.

(A) is a side view of a recording apparatus including a liquid ejection head according to an embodiment of the present invention, and (b) is a plan view. FIG. 2 is a plan view of a head body that is a main part of the liquid ejection head of FIG. 1. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. FIG. 3 is an enlarged view of a region surrounded by an alternate long and short dash line in FIG. It is a longitudinal cross-sectional view along the VV line of FIG. FIG. 3 is an enlarged plan view of a main part of the head main body of FIG. 2. It is an enlarged plan view of the plate of the same area | region as FIG. (A), (b) is an enlarged plan view of the principal part of the plate used for the head main body which concerns on other embodiment of this invention.

  FIG. 1A is a schematic side view of a color inkjet printer 1 (hereinafter sometimes simply referred to as a printer) which is a recording apparatus including a liquid discharge head 2 according to an embodiment of the present invention. FIG. 1B is a schematic plan view of the printer 1. The printer 1 moves the print paper P relative to the liquid ejection head 2 by transporting the print paper P as a recording medium from the guide roller 82 </ b> A to the transport roller 82 </ b> B. The control unit 88 controls the liquid ejection head 2 based on image or character data to eject liquid toward the recording medium P, land droplets on the printing paper P, and print on the printing paper P. Record such as.

  In the present embodiment, the liquid discharge head 2 is fixed to the printer 1, and the printer 1 is a so-called line printer. As another embodiment of the recording apparatus, the liquid ejection head 2 is moved by reciprocating in a direction intersecting the transport direction of the printing paper P, for example, in a direction substantially perpendicular to the transporting direction of the printing paper P. There is a so-called serial printer that alternately conveys the printing paper P.

  A flat head mounting frame 70 (hereinafter sometimes simply referred to as a frame) is fixed to the printer 1 so as to be substantially parallel to the printing paper P. The frame 70 is provided with 20 holes (not shown). In the frame 70, 20 liquid discharge heads 2 are mounted in the respective hole portions, and the portion of the liquid discharge head 2 that discharges the liquid faces the printing paper P. The distance between the liquid ejection head 2 and the printing paper P is, for example, about 0.5 mm to 20 mm. The five liquid ejection heads 2 constitute one head group 72, and the printer 1 has four head groups 72.

  The liquid discharge head 2 has a long and narrow shape in the direction from the front to the back in FIG. 1A and in the vertical direction in FIG. This long direction is sometimes called the longitudinal direction. In one head group 72, the three liquid ejection heads 2 are arranged along a direction intersecting the transport direction of the printing paper P, for example, a direction substantially perpendicular to the transport direction of the printing paper P, and the other two The two liquid discharge heads 2 are arranged one by one between the three liquid discharge heads 2 at positions shifted along the transport direction. The liquid discharge heads 2 are arranged so that the printable range of each liquid discharge head 2 is connected in the width direction of the print paper P (in the direction intersecting the conveyance direction of the print paper P) or the ends overlap. Thus, printing without gaps in the width direction of the printing paper P is possible.

  The four head groups 72 are arranged along the conveyance direction of the recording paper P. A liquid, for example, ink is supplied to each liquid ejection head 2 from a liquid tank (not shown). The liquid discharge heads 2 belonging to one head group 72 are supplied with the same color ink, and the four head groups 72 can print four color inks. The colors of ink ejected from each head group 72 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). A color image can be printed by printing such ink under the control of the control unit 88.

  The number of the liquid discharge heads 2 mounted on the printer 1 may be one if it is a single color and the range that can be printed by one liquid discharge head 2 is printed. The number of the liquid ejection heads 2 included in the head group 72 or the number of the head groups 72 can be appropriately changed depending on the printing target and printing conditions. For example, the number of head groups 72 may be increased in order to perform multicolor printing. Also, if a plurality of head groups 72 that print in the same color are arranged and printed alternately in the transport direction, the transport speed can be increased even if the liquid ejection heads 2 having the same performance are used. Thereby, the printing area per time can be increased. Alternatively, a plurality of head groups 72 for printing in the same color may be prepared and arranged so as to be shifted in a direction crossing the transport direction, so that the resolution in the width direction of the print paper P may be increased.

  Further, in addition to printing colored inks, a liquid such as a coating agent may be printed for surface treatment of the printing paper P.

  The printer 1 performs printing on the printing paper P. The printing paper P is wound around the paper feed roller 80A, passes between the two guide rollers 82A, passes through the lower side of the liquid ejection head 2 mounted on the frame 70, and thereafter It passes between the two conveying rollers 82B and is finally collected by the collecting roller 80B. When printing, the printing paper P is transported at a constant speed by rotating the transport roller 82 </ b> B and printed by the liquid ejection head 2. The collection roller 80B winds up the printing paper P sent out from the conveyance roller 82B. The conveyance speed is, for example, 75 m / min. Each roller may be controlled by the controller 88 or may be manually operated by a person.

  In addition to the printing paper P, the recording medium may be a roll-like cloth. Further, instead of directly transporting the printing paper P, the printer 1 may transport the transport belt directly and transport the recording medium placed on the transport belt. In this way, a sheet or a cut cloth, wood, tile or the like can be used as a recording medium. Furthermore, a wiring pattern of an electronic device may be printed by discharging a liquid containing conductive particles from the liquid discharge head 2. Furthermore, a chemical may be produced by discharging a predetermined amount of liquid chemical agent or a liquid containing a chemical agent from the liquid discharge head 2 toward the reaction container or the like and reacting.

  In addition, a position sensor, a speed sensor, a temperature sensor, and the like may be attached to the printer 1, and the control unit 88 may control each part of the printer 1 according to the state of each part of the printer 1 that can be understood from information from each sensor. . For example, the temperature of the liquid discharge head 2, the temperature of the liquid in the liquid tank, the pressure applied by the liquid in the liquid tank to the liquid discharge head 2, etc., can be used for the discharge characteristics of the discharged liquid, such as the discharge amount or the discharge speed. When there is an influence, the drive signal for ejecting the liquid may be changed according to the information.

  Next, the liquid ejection head 2 according to an embodiment of the present invention will be described. FIG. 2 is a plan view showing a head main body 2a which is a main part of the liquid ejection head 2 shown in FIG. FIG. 3 is an enlarged plan view of a region surrounded by a one-dot chain line in FIG. 2, and is a part of the head main body 2a. In FIG. 3, for the sake of explanation, some of the flow paths are omitted. FIG. 4 is an enlarged plan view at the same position as FIG. 3, and a part of the flow path different from FIG. 3 is omitted. FIG. 5 is a longitudinal sectional view taken along line VV in FIG. FIG. 6 is an enlarged plan view of a main part of the head main body 2a of FIG. FIG. 7 is an enlarged plan view of the plate 4b in the same region as FIG. 3 and 4, in order to make the drawings easy to understand, the pressurizing chamber 10, the squeezing 6, the discharge hole 8, and the like that are to be drawn by broken lines below the piezoelectric actuator substrate 21 are drawn by solid lines.

  In addition to the head main body 2a, the liquid discharge head 2 may include a reservoir or a casing for supplying liquid to the head main body 2a. The head body 2a includes a flow path member 4 and a piezoelectric actuator substrate 21 in which a displacement element 30 that is a pressurizing unit is formed.

  The flow path member 4 constituting the head body 2a includes a manifold 5 which is a common flow path, a plurality of pressurizing chambers 10 connected to the manifold 5, and a plurality of discharge holes respectively connected to the plurality of pressurizing chambers 10. 8 and. The pressurizing chamber 10 opens to the upper surface of the flow path member 4, and the upper surface of the flow path member 4 is a pressurizing chamber surface 4-2. The upper surface of the flow path member 4 has an opening 5a connected to the manifold 5, and liquid is supplied from the opening 5a.

  In addition, a piezoelectric actuator substrate 21 including a displacement element 30 is joined to the upper surface of the flow path member 4, and each displacement element 30 is disposed on the pressurizing chamber 10. The piezoelectric actuator substrate 21 is connected to a signal transmission unit 60 that supplies a signal to each displacement element 30. In FIG. 2, the outline of the vicinity of the signal transmission unit 60 connected to the piezoelectric actuator substrate 21 is indicated by a dotted line so that the two signal transmission units 60 are connected to the piezoelectric actuator substrate 21. The electrodes formed on the signal transmission unit 60 that are electrically connected to the piezoelectric actuator substrate 21 are arranged in a rectangular shape at the end of the signal transmission unit 60. The two signal transmission parts 60 are connected so that each end comes to the center part in the short direction of the piezoelectric actuator substrate 21.

  The head body 2 a has a flat channel member 4. The head body 2 a has one piezoelectric actuator substrate 21 including the displacement element 30 joined on the flow path member 4. The planar shape of the piezoelectric actuator substrate 21 is rectangular, and is arranged on the upper surface of the flow path member 4 so that the long side of the rectangle is along the longitudinal direction of the flow path member 4.

  Two manifolds 5 are formed inside the flow path member 4. The manifold 5 has an elongated shape extending from one end side in the longitudinal direction of the flow path member 4 to the other end side. That is, the manifold 5 is long in one direction. In the present embodiment, the one direction is the same as the longitudinal direction of the liquid ejection head 2. Further, the manifold 5 is formed with openings 5 a that are open on the upper surface of the flow path member 4 at both ends thereof.

  The manifold 5 is partitioned by a partition wall 15 provided at an interval in the short-side direction at least in the central portion in the longitudinal direction, which is a region connected to the pressurizing chamber 10. The partition wall 15 has the same height as the manifold 5 in the central portion in the longitudinal direction, which is a region connected to the pressurizing chamber 10, and completely separates the manifold 5 into a plurality of sub-manifolds 5b. By doing so, it is possible to provide the discharge hole 8 and the flow path connected from the discharge hole 8 to the pressurizing chamber 10 so as to overlap with the partition wall 15 in a plan view.

  The portion of the manifold 5 divided into a plurality of parts may be referred to as a sub-manifold 5b. In the present embodiment, two manifolds 5 are provided independently, and openings 5a are provided at both ends. One manifold 5 is provided with seven partition walls 15 and divided into eight sub-manifolds 5b. The width of the sub-manifold 5b is larger than the width of the partition wall 15, so that a large amount of liquid can flow through the sub-manifold 5b.

  The flow path member 4 is formed by two-dimensionally expanding a plurality of pressurizing chambers 10. The pressurizing chamber 10 is a hollow region having a substantially rhombic or elliptical planar shape with rounded corners.

  The pressurizing chamber 10 is connected to one sub-manifold 5 b through the throttle 6. Along with one sub-manifold 5b, two pressurizing chamber rows 11, which are rows of pressurizing chambers 10 connected to the sub-manifold 5b, are provided on each side of the sub-manifold 5b, for a total of two rows. Yes. Accordingly, 16 rows of pressurizing chambers 11 are provided for one manifold 5, and 32 heads of pressurizing chambers 11 are provided in the entire head body 2a. The intervals in the longitudinal direction of the pressurizing chambers 10 in the respective pressurizing chamber rows 11 are the same, for example, 37.5 dpi.

  One column of dummy pressurizing chambers 16 is provided at the end of each pressurizing chamber row 11. The dummy pressurizing chambers 16 in the dummy pressurizing chamber row are connected to the manifold 5 but are not connected to the discharge holes 8. Further, one dummy pressurizing chamber row in which dummy pressurizing chambers 16 are arranged in a straight line is provided outside the 32 pressurizing chamber rows 11. The dummy pressurizing chamber 16 in this dummy pressurizing chamber row is not connected to either the manifold 5 or the discharge hole 8. By these dummy pressurizing chambers 16, the structure (rigidity) around the pressurizing chamber 10 one inner side from the end is close to the structure (rigidity) of the other pressurizing chambers 10, so that the difference in liquid ejection characteristics is reduced. Less. In addition, since the influence of the surrounding structure difference has a large influence on the pressurizing chambers 10 adjacent to each other in the length direction, the dummy pressurizing chambers are provided at both ends in the length direction. Since the influence in the width direction is relatively small, it is provided only on the side closer to the end of the head body 21a. Thereby, the width | variety of the head main body 21a can be made small.

  The pressurizing chambers 10 connected to one manifold 5 are arranged in a lattice form having rows and columns along each outer side of the rectangular piezoelectric actuator substrate 21. As a result, the individual electrodes 25 formed on the pressurizing chamber 10 are arranged at equal distances from the outer side of the piezoelectric actuator substrate 21. Therefore, when forming the individual electrodes 25, the piezoelectric actuator substrate is formed. 21 can be hardly deformed. When the piezoelectric actuator substrate 21 and the flow path member 4 are joined, if this deformation is large, stress may be applied to the displacement element 30 near the outer side, resulting in variations in displacement characteristics. However, by reducing the deformation, The variation can be reduced. In addition, since the dummy pressurizing chamber row of the dummy pressurizing chamber 16 is provided outside the pressurizing chamber row 11 closest to the outer side, the influence of deformation can be made less susceptible. The pressurizing chambers 10 belonging to the pressurizing chamber row 11 are arranged at equal intervals, and the individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals. The pressurizing chamber rows 11 are arranged at equal intervals in the short direction, and the rows of the individual electrodes 25 corresponding to the pressurizing chamber rows 11 are also arranged at equal intervals in the short direction. Thereby, it is possible to eliminate a portion where the influence of the crosstalk becomes particularly large.

  In the present embodiment, the pressurizing chambers 10 are arranged in a lattice shape, but the pressurizing chambers 10 of adjacent pressurizing chamber rows 11 may be arranged in a staggered manner so as to be positioned between each other. By doing so, the distance between the pressurizing chambers 10 belonging to the adjacent pressurizing chamber rows 11 becomes longer, so that crosstalk can be further suppressed.

  Regardless of how the pressurizing chamber rows 11 are arranged, when the flow path member 4 is viewed in plan, the pressurizing chamber 10 belonging to one pressurizing chamber row 11 is added to the adjacent pressurizing chamber row 11. By arranging the pressure chamber 10 and the liquid discharge head 2 so as not to overlap in the longitudinal direction, crosstalk can be suppressed. On the other hand, when the distance between the pressurizing chamber rows 11 is increased, the width of the liquid discharge head 2 is increased, so that the accuracy of the installation angle of the liquid discharge head 2 relative to the printer 1 and the use of a plurality of liquid discharge heads 2 are increased. The influence of the relative position accuracy of the liquid discharge head 2 on the printing result is increased. Therefore, by making the width of the partition wall 15 smaller than that of the sub-manifold 5b, the influence of the accuracy on the printing result can be reduced.

  The pressurizing chamber 10 connected to one sub-manifold 5 b forms two rows of pressurizing chamber rows 11, and the discharge holes 8 connected to the pressurizing chambers 10 belonging to one pressurizing chamber row 11 are One discharge hole row 9 is formed. The discharge holes 8 connected to the pressurizing chambers 10 belonging to the two pressurizing chamber rows 11 open to different sides of the sub-manifold 5b. In FIG. 4, two discharge hole rows 9 are provided in the partition wall 15, but the discharge holes 8 belonging to each discharge hole row 9 are connected to the sub-manifold 5 b on the side close to the discharge holes 8 in the pressurizing chamber 10. Are connected through. When the discharge hole 8 connected to the adjacent sub-manifold 5b via the pressurizing chamber row 11 and the liquid discharge head 2 are arranged so as not to overlap in the longitudinal direction, the pressurizing chamber 10 and the discharge hole 8 are connected. Since crosstalk between the flow paths can be suppressed, crosstalk can be further reduced. If the entire flow path connecting the pressurizing chamber 10 and the discharge hole 8 is arranged so as not to overlap in the longitudinal direction of the liquid discharge head 2, crosstalk can be further reduced.

  A plurality of pressurizing chambers are formed by a plurality of pressurizing chambers 10 connected to one manifold 5. Since there are two manifolds 5, there are two pressurizing chamber groups. The arrangement of the pressurizing chambers 10 related to ejection in each pressurizing chamber group is the same, and is arranged at a position translated in the short direction. These pressurizing chambers 10 are arranged over almost the entire surface although there are portions where the gaps between the pressurizing chamber groups are slightly wide in the region facing the piezoelectric actuator substrate 21 on the upper surface of the flow path member 4. . That is, the pressurizing chamber group formed by these pressurizing chambers 10 occupies a region having almost the same shape as the piezoelectric actuator substrate 21. Further, the opening of each pressurizing chamber 10 is closed by bonding the piezoelectric actuator substrate 21 to the upper surface of the flow path member 4.

  From the corner portion of the pressurizing chamber 10 facing the corner portion to which the squeezing 6 is connected, the flow channel connected to the discharge hole 8 opened on the discharge hole surface 4-1 on the lower surface of the flow channel member 4 extends. . This flow path extends in a direction away from the pressurizing chamber 10 in a plan view. More specifically, the pressurizing chamber 10 extends away from the direction along the long diagonal line while being shifted to the left and right with respect to that direction. As a result, the discharge chambers 8 can be arranged at intervals of 1200 dpi as a whole, while the pressurization chambers 10 are arranged in a lattice pattern in which the intervals within the pressurization chamber rows 11 are 37.5 dpi.

  In other words, when the discharge holes 8 are projected so as to be orthogonal to the virtual straight line parallel to the longitudinal direction of the flow path member 4, each manifold 5 is within the range of R of the virtual straight line shown in FIG. That is, 16 discharge holes 8 connected to, and a total of 32 discharge holes 8 are equally spaced by 1200 dpi. Thus, by supplying the same color ink to all the manifolds 5, an image can be formed with a resolution of 1200 dpi in the longitudinal direction as a whole. Further, one discharge hole 8 connected to one manifold 5 is equally spaced at 600 dpi within the range of R of the imaginary straight line. As a result, by supplying different colors of ink to the respective manifolds 5, it is possible to form two-color images with a resolution of 600 dpi in the longitudinal direction as a whole. In this case, if two liquid ejection heads 2 are used, an image of four colors can be formed with a resolution of 600 dpi, and printing accuracy is higher than when four liquid ejection heads capable of printing at 600 dpi are used. Can also be done easily. In addition, the range of R of the imaginary straight line is covered with the discharge holes 8 connected to the pressurizing chambers 10 belonging to the one pressurizing chamber row arranged in the short direction of the head main body 2a.

  Individual electrodes 25 are formed at positions facing the pressurizing chambers 10 on the upper surface of the piezoelectric actuator substrate 21. The individual electrode 25 includes an individual electrode main body 25a that is slightly smaller than the pressurizing chamber 10 and has a shape substantially similar to the pressurizing chamber 10, and an extraction electrode 25b that is extracted from the individual electrode main body 25a. Yes. As with the pressurizing chamber 10, the individual electrodes 25 constitute an individual electrode row and an individual electrode group. A common electrode surface electrode 28 is disposed on the upper surface of the piezoelectric actuator substrate 21. The common electrode surface electrode 28 and the common electrode 24 are electrically connected through a through conductor (not shown) disposed in the piezoelectric ceramic layer 21b.

  The discharge hole 8 is disposed at a position that avoids a region facing the manifold 5 disposed on the lower surface side of the flow path member 4. Further, the discharge hole 8 is disposed in a region facing the piezoelectric actuator substrate 21 on the lower surface side of the flow path member 4. These discharge holes 8 occupy a region having almost the same shape as the piezoelectric actuator substrate 21 as one group, and a droplet is discharged from the discharge hole 8 by displacing the displacement element 30 of the corresponding piezoelectric actuator substrate 21. Discharged.

  The flow path member 4 is configured by bonding a plurality of plates to each other with an adhesive. That is, the flow path member 4 has a laminated structure in which a plurality of plates are bonded and laminated. These plates are a cavity plate 4a, an aperture plate 4b, a supply plate 4c, manifold plates 4d to i, a cover plate 4j, and a nozzle plate 4k in order from the upper surface of the flow path member 4. A number of holes are formed in these plates. When the thickness of each plate is about 10 μm to 300 μm, the formation accuracy of the holes to be formed can be increased. The thickness of the flow path member 4 is about 500 μm to 2 mm. Each plate is aligned and laminated so that these holes communicate with each other to form the individual flow path 12 and the manifold 5. In the head main body 2a, the pressurizing chamber 10 is on the upper surface of the flow path member 4, the manifold 5 is on the inner lower surface side, the discharge holes 8 are on the lower surface, and the parts constituting the individual flow path 12 are close to each other in different positions. The manifold 5 and the discharge hole 8 are connected via the pressurizing chamber 10.

  The holes formed in each plate will be described. These holes include the following. The first is the pressurizing chamber 10 formed in the cavity plate 4a. Secondly, there is a communication hole that forms a squeeze 6 that connects from one end of the pressurizing chamber 10 to the manifold 5. This communication hole is formed in each plate from the aperture plate 4b (specifically, the inlet of the pressurizing chamber 10) to the supply plate 4c (specifically, the outlet of the manifold 5). The squeezing 6 will be described in detail later.

  Thirdly, the descender 7 is a partial flow path that constitutes a flow path that communicates with the discharge hole 8 from the other end opposite to the end to which the squeezing 6 of the pressurizing chamber 10 is connected. The descender 7 is formed on each plate from the base plate 4b (specifically, the outlet of the pressurizing chamber 10) to the nozzle plate 4l (specifically, the discharge hole 8).

  Fourthly, there is a communication hole constituting the sub-manifold 5a. The communication holes are formed in the manifold plates 4e to 4j. Holes are formed in the manifold plates 4e to 4j so that the partition portions to be the partition walls 15 remain so as to constitute the sub-manifold 5b. The partition portion in each manifold plate 4e-j is connected to each manifold plate 4e-j by a half-etched support portion (not shown in the figure).

  The first to fourth communication holes are connected to each other to form an individual flow path 12 from the liquid inflow port (outlet of the manifold 5) to the discharge hole 8 from the manifold 5. The liquid supplied to the manifold 5 is discharged from the discharge hole 8 through the following path. First, the manifold 5 reaches the one end of the aperture 6 upward. Next, it proceeds horizontally along the extending direction of the restriction 6 and reaches the other end of the restriction 6. From there, it reaches one end of the pressurizing chamber 10 upward. Furthermore, it progresses horizontally along the extending direction of the pressurizing chamber 10 and reaches the other end of the pressurizing chamber 10. The liquid that has entered the descender 7 from the pressurizing chamber 10 moves in the horizontal direction and is mainly directed downward and reaches the discharge hole 8 that is open on the lower surface, and is discharged to the outside.

The piezoelectric actuator substrate 21 has a laminated structure composed of two piezoelectric ceramic layers 21a and 21b which are piezoelectric bodies. Each of these piezoelectric ceramic layers 21a and 21b has a thickness of about 20 μm. The thickness from the lower surface of the piezoelectric ceramic layer 21a of the piezoelectric actuator substrate 21 to the upper surface of the piezoelectric ceramic layer 21b is about 40 μm. Both of the piezoelectric ceramic layers 21 a and 21 b extend so as to straddle the plurality of pressure chambers 10. The piezoelectric ceramic layers 21a, 21b may, for example, strength with a dielectric, lead zirconate titanate (PZT), NaNbO ₃ system, BaTiO ₃ system, (BiNa) NbO ₃ system, such as BiNaNb ₅ O ₁₅ system Made of ceramic material. The piezoelectric ceramic layer 21a functions as a vibration plate and does not necessarily have to be a piezoelectric body. Instead, other ceramic layers or metal plates that are not piezoelectric bodies may be used.

  The piezoelectric actuator substrate 21 includes a common electrode 24 made of a metal material such as Ag—Pd and an individual electrode 25 made of a metal material such as Au. The common electrode 24 has a thickness of about 2 μm, and the individual electrode 25 has a thickness of about 1 μm.

  The individual electrodes 25 are respectively arranged at positions facing the pressurizing chambers 10 on the upper surface of the piezoelectric actuator substrate 21. The individual electrode 25 has a planar shape slightly smaller than that of the pressurizing chamber main body 10a and has a shape substantially similar to the pressurizing chamber main body 10a, and an extraction electrode drawn from the individual electrode main body 25a. 25b. A connection electrode 26 is disposed at a portion of one end of the extraction electrode 25 b that is extracted outside the region facing the pressurizing chamber 10. The connection electrode 26 is a conductive resin containing conductive particles such as silver particles, and is formed with a thickness of about 5 μm to 200 μm. Further, the connection electrode 26 is electrically joined to an electrode provided in the signal transmission unit 60.

  Although details will be described later, a drive signal is supplied from the control unit 88 to the individual electrode 25 through the signal transmission unit 60. The drive signal is supplied in a constant cycle in synchronization with the conveyance speed of the print medium P.

  The common electrode 24 is formed over substantially the entire surface in the region between the piezoelectric ceramic layer 21b and the piezoelectric ceramic layer 21a. That is, the common electrode 24 extends so as to cover all the pressurizing chambers 10 in the region facing the piezoelectric actuator substrate 21. The common electrode 24 is connected to the common electrode surface electrode 28 formed on the piezoelectric ceramic layer 21b so as to avoid the electrode group composed of the individual electrodes 44 via a through conductor formed through the piezoelectric ceramic layer 21b. It is connected. Further, the common electrode 24 is grounded via the common electrode surface electricity 28 and is held at the ground potential. Similar to the individual electrode 25, the common electrode surface electrode 28 is directly or indirectly connected to the control unit 88.

  A portion sandwiched between the individual electrode 25 and the common electrode 24 of the piezoelectric ceramic layer 21b is polarized in the thickness direction, and becomes a displacement element 30 having a unimorph structure that is displaced when a voltage is applied to the individual electrode 25. Yes. More specifically, when an electric field is applied in the polarization direction to the piezoelectric ceramic layer 21b by setting the individual electrode 25 to a potential different from that of the common electrode 24, an active portion where the applied electric field is distorted by the piezoelectric effect. Work as. In this configuration, when the control unit 88 sets the individual electrode 25 to a predetermined positive or negative potential with respect to the common electrode 24 so that the electric field and the polarization are in the same direction, the portion sandwiched between the electrodes of the piezoelectric ceramic layer 21b. (Active part) contracts in the surface direction. On the other hand, the piezoelectric ceramic layer 21a, which is an inactive layer, is not affected by an electric field, so that it does not spontaneously shrink and tries to restrict deformation of the active portion. As a result, there is a difference in strain in the polarization direction between the piezoelectric ceramic layer 21a and the piezoelectric ceramic layer 21b, and the piezoelectric ceramic layer 21a is deformed so as to protrude toward the pressurizing chamber 10 side.

  Next, the liquid discharge operation will be described. Based on the control from the control unit 88, the displacement element 30 is driven (displaced) by the drive signal supplied to the individual electrode 25. In the present embodiment, liquid can be ejected by various driving signals. Here, a so-called strike driving method will be described.

  The individual electrode 25 is set to a potential higher than the common electrode 24 (hereinafter referred to as “high potential”) in advance, and the individual electrode 25 is once at the same potential as the common electrode 24 (hereinafter referred to as “low potential”) every time there is a discharge request. Then, the potential is again set to a high potential at a predetermined timing. As a result, the piezoelectric ceramic layers 21a and 21b return to the original flat shape at the timing when the individual electrode 25 becomes low potential, and the volume of the pressurizing chamber 10 is compared with the initial state (the state where the potentials of both electrodes are different). Increase. As a result, a negative pressure is applied to the liquid in the pressurizing chamber 10. Then, the liquid in the pressurizing chamber 10 starts to vibrate with the natural vibration period. Specifically, first, the volume of the pressurizing chamber 10 begins to increase, and the negative pressure gradually decreases. Next, the volume of the pressurizing chamber 10 becomes maximum and the pressure becomes almost zero. Next, the volume of the pressurizing chamber 10 begins to decrease, and the pressure increases. Thereafter, the individual electrode 25 is set to a high potential at a timing at which the pressure becomes substantially maximum. Then, the first applied vibration overlaps with the next applied vibration, and a larger pressure is applied to the liquid. This pressure propagates through the descender 7 to discharge the liquid from the discharge hole 8.

  In other words, a droplet can be ejected by supplying a pulse driving signal that is a low potential for a certain period with the high potential as a reference to the individual electrode 25. If this pulse width is AL (Acoustic Length), which is half the time of the natural vibration period of the liquid in the pressurizing chamber 10, in principle, the discharge speed and discharge amount of the liquid can be maximized. The natural vibration period of the liquid in the pressurizing chamber 10 is greatly influenced by the physical properties of the liquid and the shape of the pressurizing chamber 10, but in addition, the physical properties of the piezoelectric actuator substrate 21 or the flow path connected to the pressurizing chamber 10. Also affected by the characteristics of.

  Note that the pulse width is actually set to a value of about 0.5 AL to 1.5 AL because there are other factors to consider, such as combining the ejected droplets into one. Further, since the discharge amount can be reduced by setting the pulse width to a value outside of AL, the pulse width is set to a value outside of AL in order to reduce the discharge amount.

  The throttle 6 connecting the sub-manifold 5a, which is a common flow path, and the pressurizing chamber 10 functions to reflect pressure waves due to the high flow path resistance in the stroke. Directly affects discharge characteristics such as discharge volume. Even when ejection is performed by pushing or other methods, reflection of the pressure wave occurs, and the pressure wave remains as a residual vibration while being attenuated in the pressurizing chamber 10 or the descender 7 and affects the next ejection. Effect. In any case, it is preferable that the flow path characteristics of the squeeze 6 have a large influence on the ejection characteristics and have small dimensional variations.

  The pressure applied to the pressurizing chamber 10 by the displacement element 30 is directed to the squeeze 6 and the descender 7. Normally, the flow of the squeeze 6 is higher than the descender 7 so that the energy is mainly used for discharge. Road resistance is increased. In particular, when discharging by pulling, the flow path resistance of the aperture 6 is increased so that reflection is likely to occur.

  In order to increase the channel resistance, it is necessary to increase the length of the channel or to reduce the cross-sectional area of the channel. When the length of the flow path is increased, the size of the head body 2a is increased. For this reason, it is necessary to reduce the cross-sectional area of the flow path.

  Therefore, the narrowing body 6a, which is a portion having a high flow resistance, is a flow path extending along the plane of the plate, that is, a flow path extending in a direction perpendicular to the stacking direction of the plates. Thus, the cross-sectional area can be reduced and the length can be increased to some extent.

  By directly connecting the narrowing body 6a extending along the plane of the plate and the pressurizing chamber 10 having a shape spreading in the plane direction of the plate, the flow path length through which the liquid actually flows due to the stacking deviation of the plates. The variation of the is increased. Therefore, an outflow hole 6c, which is a hole extending in the plate stacking direction, is arranged on the side of the pressure body 6a in the pressurizing chamber 10 so that the body 6a and the pressure chamber 10 are connected via the outflow hole 6c. To. Similarly, the squeezing main body 6a and the sub-manifold 5a are connected via an inflow hole 6b that is a hole extending in the stacking direction of the plates.

  Details of the arrangement of the aperture 6 will be described with reference to FIG. In FIG. 6, the descender 7 that connects the pressurizing chamber 10 and the discharge hole 8 is omitted in shape, and the connection is represented by a line. On both sides of the sub-manifold 5a, pressurizing chamber columns 11 that are columns of the pressurizing chambers 10 are disposed along the sub-manifold 5a, one row at a time, for a total of two rows. In FIG. 6, the pressurizing chamber row 11 disposed on the left side of the sub-manifold 5a is referred to as a first pressurizing chamber row 11A, and the pressurizing chamber row 11 disposed on the right side is described as a second pressurizing chamber row 11B. To do. Further, the direction (left-right direction in FIG. 6) orthogonal to the direction (one direction) in which the sub-manifold 5a extends is defined as the other direction. In FIG. 6, the right side is one side in the other direction, and the left side is the other side in the other direction.

  The pressurizing chambers 10 belonging to the first pressurizing chamber row 11A and the sub-manifold 5a are connected via the first throttle 6A. A first inflow hole 6Ab, a first restriction body 6Aa, and a first outflow hole 6Ac are arranged in order from the sub-manifold 5a side in the first restriction 6A. The pressurizing chambers 10 belonging to the second pressurizing chamber row 11B and the sub-manifold 5a are connected via the second throttle 6B. In the second squeezing 6B, a second inflow hole 6Bb, a second squeezing main body 6Ba, and a second outflow hole 6Bc are arranged in this order from the sub-manifold 5a side.

  The first squeezing main body 6Aa and the second squeezing main body 6Ba are flow paths through which liquid flows in the plane direction of the plate. The first squeezing main body 6Aa and the second squeezing main body 6Ba are configured by grooves disposed on the lower surface of the plate 4b. More specifically, the grooves are closed by the upper surface of the plate 4c to form a flow path. ing. The first narrowing main body 6Aa and the second narrowing main body 6Ba are linear and substantially constant width flow paths. The first restriction body 6Aa and the second restriction body 6Ba extend in a direction intersecting with one direction, and are arranged alternately in one direction. In addition, it is preferable that the angle between the one direction and the direction in which the first squeezing main body 6Aa and the second squeezing main body 6Ba extend is 45 degrees or more so that the density of the squeezing 6 can be increased. Further, this angle is more preferably 60 degrees or more, particularly 75 degrees or more.

  The first inflow hole 6Ab is a flow path through which liquid flows in the plate stacking direction, and is a cylindrical flow path from the upper surface of the groove disposed in the plate 4b to the lower surface of the plate 4c. A first outflow hole 6Ac is connected to the pressurizing chamber 10 side of the first squeezing body 6Aa. The first outflow hole 6Ac is a channel through which the liquid flows in the plate stacking direction, and is a cylindrical channel from the upper surface of the plate 4b to the lower surface of the plate 4b. A first inflow hole 6Ab is connected to the sub-manifold 5a side of the first restriction body 6Aa. Accordingly, the plate 4b has a linear first squeezing main body 6Aa, a first squeezing hole 6Ac having a wider opening than the first squeezing main body 6Aa arranged at one end thereof, and the other end thereof. The first inflow hole 6Ab having a wider opening than the first restricting body 6Aa that is arranged is arranged. Also in the second restriction 6B, the second restriction body 6Ba, the second inflow hole 6Bb, and the second outflow hole 6Bc have the same relationship.

  When the plates 4b and 4c are bonded and laminated, the adhesive supplied between them may flow into the first and second apertures 6A and 6B. However, since the first squeezing 6A and the second squeezing 6B are alternately arranged almost in parallel, each other serves as a release groove for the adhesive, so that the flow of the adhesive can be suppressed. Specifically, since the second squeezing 6B is arranged on both sides of the first squeezing 6A, the adhesive hardly flows into the first squeezing 6A beyond the second squeezing 6B. In addition, even if the amount of adhesive supplied between the first squeezing 6A and the second squeezing 6B is excessive, it will flow about half by half into the first squeezing 6A and the second squeezing 6B. The amount of adhesive flowing in can be reduced.

  Next, the adhesive that flows into the first outflow hole 6Ac will be considered. Since the first outflow hole 6Ac is disposed between two adjacent second apertures 6B, the adhesive flows from the upper side and the lower side in FIG. 6 into the first outflow hole 6Ac. Can be suppressed. Further, the two adjacent second apertures 6B extend from the position of the first outflow hole 6Ac toward the right side of FIG. 6 in the other direction, that is, the left-right direction in FIG. 6, and thus the first outflow hole 6Ac. The flow of the adhesive from the right side of FIG. Here, the second inflow hole 6Bb is disposed on the other side in the other direction than the first outflow hole 6Ac (that is, the left side in the left-right direction in FIG. 6). The width of the opening of the second inflow hole 6Bb is wider than the width of the opening of the first outflow hole 6Ac. For this reason, a part of the adhesive that is about to flow into the first outflow hole 6Ac from the left side in FIG. 6 is stopped by the second inflow hole 6Bb, and can hardly flow into the first outflow hole 6Ac.

  Here, the “width of the opening” refers to the diameter of the hole when the plate is viewed in plan. When the hole is not circular but rectangular, for example, in plan view, the “opening width” described above connects the short sides facing each other, that is, the length of the long side, and has the longest diameter. Say the big part.

  Moreover, the above-mentioned “the width of the opening of the second inflow hole 6Bb is wider than the width of the opening of the first outflow hole 6Ac” means that the width of the opening is widened due to a manufacturing error. is there. Further, “the width of the opening of the second inflow hole 6Bb is wider than the width of the opening of the first outflow hole 6Ac” means that all of the second inflow hole 6Bb and the first outflow hole 6Ac have such a relationship. It is not necessary to have such a relationship. In other words, the width of the opening of one second inflow hole 6Bb only needs to be wider than the width of the opening of one adjacent first outflow hole 6Ac. In addition, it is preferable that all of 2nd inflow hole 6Bb and 1st outflow hole 6Ac have said relationship.

  The same applies to the relationship between the first inflow hole 6Ab and the second outflow hole 6Bc.

  Moreover, it is preferable that 1st outflow hole 6Ac is arrange | positioned between 2nd squeezing main bodies 6Ba. According to this configuration, the position of the second inflow hole 6Bb is disposed on the other side in the other direction from the first outflow hole 6Ac, and the adhesive from the left side in FIG. 6 to the first outflow hole 6Ac Inflow can be further suppressed.

  The same applies to the second outflow hole 6Bc. Specifically, the first inflow hole 6Ab is disposed on one side in the other direction (that is, the right side in the left-right direction in FIG. 6) than the second outflow hole 6Bc. The width of the opening of the first inflow hole 6Ab is wider than the width of the opening of the second outflow hole 6Bc. For this reason, a part of the adhesive that is about to flow into the second outflow hole 6Bc from the right side in FIG. 6 is stopped by the first inflow hole 6Ab, and can hardly flow into the second outflow hole 6Bc.

  Moreover, it is preferable that 2nd outflow hole 6Bc is arrange | positioned between 1st squeezing main bodies 6Aa. According to this configuration, the position of the first inflow hole 6Ab is arranged on one side in the other direction from the second outflow hole 6Bc, and the adhesive from the right side in FIG. 6 to the second outflow hole 6Bc Inflow can be further suppressed.

  The squeezing main body 6 a is a portion having a high flow path resistance in the squeezing 6 and mainly plays a role of reflecting the pressure wave transmitted from the pressurizing chamber 10. The outflow hole 6c has a larger cross-sectional area with respect to the direction in which the liquid flows, and the flow path resistance is lower than that of the squeezing body 6a. Therefore, even if the flow path resistance of the outflow hole 6c fluctuates, the influence on the flow path resistance of the entire aperture 6 is relatively small. From this point of view, it is desirable to increase the cross-sectional area of the outflow hole 6c. However, when the outflow hole 6b has a shape wider than the pressurizing chamber 10 or the squeezing body 6a, liquid is formed in the widened portion. Tends to stay. If there is such stagnation, the solid content of the liquid is likely to stick, which is not preferable. That is, it is not preferable to make the outflow hole 6c unnecessarily large.

  On the other hand, the inflow hole 6b is connected to the sub-manifold 5a. Even if the inflow hole 6b is enlarged, the sub-manifold 5a connected to the inflow hole 6b is larger. Therefore, by increasing the inflow hole 6b, that is, by increasing the width of the opening of the inflow hole 6b, and narrowing the width of the portion that becomes the path through which the adhesive flows into the outflow hole 6c, the flow resistance of the outflow hole 6c is dispersed. Can be small.

  The holes constituting the first and second restricting bodies 6Aa and 6Ba may be holes arranged in one plate. In that case, the upper side of the hole is closed by the lower surface of the plate laminated thereon, and the lower side of the hole is closed by the upper surface of the plate laminated below. Considering the occurrence of misalignment between the plates, if the first and second main body 6Aa and 6Ba are configured with grooves or holes arranged in one plate, a plurality of plates This is more preferable than the case where the arranged grooves or holes are combined and the flow path characteristics are less likely to be changed due to misalignment.

  Moreover, it is preferable that 1st squeezing main body 6Aa and 2nd squeezing main body 6Ba are comprised by the groove | channel as mentioned above. When it is composed of holes, two layers of adhesive will flow when laminating the plate where the holes are arranged, the plate above it, and the plate below it, but it is composed of grooves. Then, the adhesive can flow into only one layer when laminating the plate in which the groove is disposed and one plate that closes the groove. Further, if the supply of the adhesive is performed on the main surface where the groove is disposed, the possibility of the adhesive being directly supplied into the groove can be reduced during lamination. This is preferable because the possibility that the adhesive is directly supplied to the main surface of the closing plate can be reduced.

  It is preferable that at least half of the length of the first squeezing main body 6Aa is sandwiched between two adjacent second squeezing main bodies 6Ba. According to this configuration, since the flow of the adhesive provided between the two second restriction main bodies 6Ba is stabilized, the variation in flow path resistance can be reduced. Similarly, it is preferable that more than half of the length of the second squeezing body 6Ba is sandwiched between two adjacent first squeezing bodies 6Aa. According to this configuration, since the flow of the adhesive provided between the two first narrowing bodies 6Aa is stabilized, the variation in flow path resistance can be reduced.

  More specifically, it is preferable that 2/3 or more of the length of the first squeezing body 6Aa is sandwiched between two adjacent second squeezing 6B. According to this configuration, since the flow of the adhesive provided between the two second apertures 6B is more stable, the variation in flow path resistance can be further reduced. Similarly, it is preferable that 2/3 or more of the length of the second squeezing main body 6Ba is sandwiched between two adjacent first squeezing 6A. According to this configuration, since the flow of the adhesive provided between the two first squeezes 6A is more stable, variation in flow path resistance can be further reduced. Furthermore, it is more preferable that the entirety is sandwiched between each other.

  The opening on the side of the sub-manifold 5a of the inflow hole 6b is preferably disposed on the upper surface of the sub-manifold 5a, and the upper surface of the sub-manifold 5a in which they are opened is disposed on the lower surface of the plate 4c. It is preferably a groove. According to this structure, it can suppress that the adhesive agent supplied between the plate 4c and the plate 4d flows into the inflow hole 6b.

  Further, it is preferable that the upper surface of the sub-manifold 5a is configured with a groove disposed on the lower surface of the plate 4c, and the squeezing body 6a is configured with a groove disposed on the lower surface of the plate 4b. According to this configuration, the entire aperture 6 including the inflow hole 6b and the outflow hole 6c can be configured by stacking the two plates 4b and 4c, so that the adhesive layer that may flow into the aperture 6 may be formed. The number can be reduced.

  Next, the adhesive relief groove 17 disposed around the squeezing 6 will be described with reference to FIG. FIG. 7 is an enlarged plan view of the same range as FIG. 6 of the plate 4b on which the grooves constituting the squeezing main body 6a are arranged.

  The following holes and grooves are arranged in the plate 4b. On the lower surface of the plate 4b, grooves serving as the first and second main body 6Aa and 6Ba are disposed. On the lower surface of the plate 4b, a groove that is a part of the first inflow hole 6Ab and a groove that is a part of the second inflow hole 6Bb are arranged. These grooves are connected to holes arranged in the plate 4c, and become the entire first inflow hole 6Ab and the entire second inflow hole 6Bb. A hole which becomes the first outflow hole 6Ac and a hole which becomes the second outflow hole 6Bc are disposed through the plate 4b.

  Also, a hole (hereinafter referred to as a hole) that is a part of the first descender 7A that penetrates the plate 4b and connects the pressurizing chamber 10 belonging to the first pressurizing chamber row 11A and the discharge hole 8 to each other. Simply called the first descender 7A). A hole that penetrates the plate 4b and forms a part of the second descender 7B that connects the pressurizing chamber 10 belonging to the second pressurizing chamber row 11B and the discharge hole 8 (hereinafter, this hole is simply referred to as a first one). 1 descender 7B).

  Further, an adhesive escape groove 17 is disposed on the lower surface of the plate. Some of them are a first escape groove 17A and a second escape groove 17B, which will be described later.

  The first inflow hole 6Ab is arranged along one direction at the right end (that is, one side in the other direction) of FIG. 7 in the sub-manifold 5a. The second descender 7B is disposed on one side in the other direction from the sub-manifold 5a along the one direction. A first escape groove 17A extending in one direction is disposed between the first inflow hole 6Ab and the second descender 7B. The first relief groove 17A can suppress the adhesive from flowing into the first inflow hole 6Ab from the right side in FIG. 7 and can suppress the adhesive from flowing into the second descender 7B from the left side in FIG.

  The first escape groove 17A is disposed at a position that does not overlap the sub-manifold 5a, that is, a position that overlaps the partition wall 15. The outer side of the sub-manifold 5a located at the end is not a so-called partition wall. However, the sub-manifold 5a including the portion is not present, and only a small hole or groove such as the descender 7 or the escape groove 17 is present. A substantially solid portion that is not disposed is referred to as a partition wall 15 for convenience.

  The state of bonding is different between the region overlapping the sub-manifold 5a and the region not overlapping the sub-manifold 5a. In the region on the partition 15, the lamination pressure is easily transmitted, and the pressure is increased, so that the adhesion is strengthened. In comparison, in the region on the sub-manifold 5a, pressure is not easily transmitted and adhesion is weak. Further, since the pressure is more strongly applied in the region on the partition wall 15, even when the adhesive is uniformly applied, the region on the partition wall 15 is bonded to the region on the sub-manifold 5a during the bonding. The agent flows.

  The first escape groove 17A can suppress the flow of the adhesive generated in this way from reaching the first inflow hole 6Ab. However, when there is only an adhesion margin around the first inflow hole 6Ab arranged on the sub-manifold 5a, the adhesion strength is relatively weak and liquid leakage or the like is likely to occur. In particular, the right side of the first inflow hole 6Ab in FIG. 7 has a narrow bonding margin and is liable to leak liquid.

  Therefore, the first escape groove 17A is disposed in a region that does not overlap with the sub-manifold 5a. By arranging in such a manner, a part of the bonding margin around the first inflow hole 6Ab, in particular, a part of the bonding margin on the right side in FIG. Therefore, liquid leakage can be suppressed.

  Similarly, a second escape groove 17B extending in one direction is disposed between the second inflow hole 6Bb and the first descender 7A. The second escape groove 17B is disposed at a position that does not overlap the sub-manifold hole 5a, can suppress the adhesive from flowing into the second inflow hole 6Bb and the first descender 7A, and adheres around the second inflow hole 6Bb. A part of the metal is disposed on the partition wall 15 and the adhesion becomes strong, so that leakage of liquid can be suppressed.

  The position depicted in FIG. 7 is the end of the sub-manifold 5a in the longitudinal direction. At the end of the sub-manifold 5a, the arrangement of the first squeezing main body 6Aa and the second squeezing main body 6Ba, which are alternately arranged, ends there. In FIG. 7, the second squeezing body 6Ba is located at the end. In FIG. 7, since the squeezing 6 is not arranged on the lower side of the second squeezing main body 6Ba at the end in FIG. 7, the adhesive flows in from the lower side of FIG. 7 as compared with the other squeezing main body 6a. The amount of the agent may increase. Therefore, an adhesive relief groove 17 is arranged on the outermost side of the second end main body 6Ba at the end in the direction in which the second main body 6Ba extends. In the example shown in FIG. 7, the escape groove 17 is disposed along the second squeezing body 6Ba. When a large amount of adhesive flows from the lower side of FIG. 7, the escape groove 17 is filled with the adhesive in one escape groove 17, and there is a possibility that the inflow cannot be sufficiently suppressed. It is preferable to arrange two or more, that is, a plurality.

  Next, another configuration for squeezing will be described. FIGS. 8A and 8B are plan views showing the main parts of the plates 104b and 204b that can be used in place of the plate 4b in the above-described embodiment. Parts having a small difference from the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the plate 104b, the first widened portion 106Aaa in which the opening width of the portion before the first inflow hole 6Ab on the first inflow hole 6Ab side of the first restriction body 106Aa is widened in the opening of the first restriction 106A. It has become. The first widened portion 106Aaa gradually increases toward the first inflow hole 6Ab. That is, 1st widening part 106Aaa is larger than the width | variety of opening of the center part of 1st squeezing main body 106Aa. By comprising in this way, the flow of the adhesive agent into 2nd outflow hole 6Bc can be suppressed more. Similarly to this, the second narrowing body 106Ba is also provided with a second widened portion 106Baa. The second widened portion 106Baa is larger than the width of the opening at the center of the second narrowing body 106Ba. Thereby, the inflow of the adhesive agent to the first outflow hole 6Ac can be further suppressed.

  Also in the plate 204b, the first widening portion 206Aaa is provided in the first narrowing body 206Aa, and the second widening portion 206Baa is provided in the second narrowing body 206Ba, as described above. That is, the first widened portion 206Aaa is larger than the width of the opening at the central portion of the first narrowing body 206Aa, and the second widened portion 206Baa is larger than the width of the opening at the central portion of the second narrowing main body 206Ba. Here, the first widened portion 206Aaa has substantially the same width as the first inflow hole 206Ab before reaching the first inflow hole 206Ab, and extends linearly with that width. The second widened portion 206Baa has substantially the same width as the second inflow hole 206Bb before reaching the second inflow hole 206Bb, and extends linearly with that width. With this configuration, the plate 4c is stacked differently, so even if the position of the first inflow hole 6Ab arranged in the plate 4c is shifted, the change in the channel resistance of the first squeezing 206A can be reduced. The same applies to the second squeeze 206.

DESCRIPTION OF SYMBOLS 1 Color inkjet printer 2 Liquid discharge head 2a Head main body 4 Flow path members 4a-l, 104b, 204b Plate of flow path member 4-1 Discharge hole surface 4-2 Pressurization chamber surface 5 Manifold 5a Manifold opening 5b Sub manifold 6 Squeeze 6a Squeeze body 6b Inflow hole 6c Outflow hole 6A, 106A, 206A First squeeze 6Aa, 106Aa, 206Aa First squeeze body 106Aaa, 206Aaa First widening part 6Ab First inflow hole 6Ac First outflow hole 6B, 106B, 206B 2 squeezing 6Ba, 106Ba, 206Ba 2nd squeezing main body 106Ba, 206Baa 2nd widening part 6Bb 2nd inflow hole 6Bc 2nd outflow hole 7 descender 7A 1st descender 7B 2nd descender 8 ejection hole 9 ejection hole row 10 pressurizing chamber 11 Pressurization room line 11 1st pressurizing chamber row 11B 2nd pressurizing chamber row 12 Individual flow path 15 Partition 16 Dummy pressurizing chamber 17 Relief groove 17A First escape groove 17B Second escape groove 21 Piezoelectric actuator substrate 21a Piezoelectric ceramic layer 21b Piezoelectric ceramic layer 24 Common electrode 25 Individual electrode 25a Individual electrode body 25b Extraction electrode 26 Connection electrode 28 Common electrode surface electrode 30 Displacement element 60 Signal transmission unit 70 Head mounting frame 72 Head group 80A Paper feed roller 80B Collection roller 82A Guide roller 82B Transport roller 88 Control Part P Printing paper

Claims (13)

A plurality of discharge holes, a plurality of pressurization chambers connected to the plurality of discharge holes, a flow path member having a common flow path for supplying a liquid to the plurality of pressurization chambers, and the plurality of pressurizations A liquid discharge head including a plurality of pressurizing units that pressurize the liquid in the chamber,
The flow path member is configured by laminating a plurality of plates in which holes or grooves serving as flow paths are arranged,
When the flow path member is viewed in plan view,
The common flow path is long in one direction,
A plurality of pressurizing chamber rows in which the plurality of pressurizing chambers are arranged are arranged in one direction on each side of the common flow path, two rows in total, and the two pressurizing chambers are arranged in one direction. If one of the rows is the first pressurizing chamber row and the other is the second pressurizing chamber row,
The pressurizing chamber belonging to the first pressurizing chamber row and the common flow path are connected via a first squeezing, and the first squeezing extends in a direction perpendicular to the stacking direction. A main body, a first inflow hole connecting the first restriction main body and the common flow path in the stacking direction on the common flow path side of the first restriction main body, and the pressure chamber side of the first restriction main body And having a first outflow hole connecting the first squeezing body and the pressurizing chamber in the stacking direction,
The pressurizing chambers belonging to the second pressurizing chamber row and the common flow path are connected via a second constriction, and the second constriction extends in a direction orthogonal to the stacking direction. A main body, a second inflow hole connecting the second restriction main body and the common flow path in the stacking direction on the common flow path side of the second restriction main body, and the pressure chamber side of the second restriction main body And having a second outflow hole connecting the second squeezing body and the pressurizing chamber in the stacking direction,
The first squeezing body and the second squeezing body extend in a direction intersecting the one direction and are alternately arranged in the one direction,
When the direction orthogonal to the one direction is the other direction,
The first inflow hole is arranged on one side in the other direction from the second outflow hole,
The second inflow hole is disposed on the other side in the other direction from the first outflow hole,
The width of the opening of the first inflow hole is larger than the width of the opening of the second outflow hole, and the width of the opening of the second inflow hole is larger than the width of the opening of the first outflow hole. head.   The said 1st outflow hole is arrange | positioned between the two said 2nd squeezing main bodies adjacent, The said 2nd outflow hole is arrange | positioned between the two said 1st squeezing main bodies adjacent. The liquid discharge head according to 1.   3. The liquid ejection head according to claim 1, wherein the holes constituting the first and second restricting bodies are arranged in one of the plurality of plates.   3. The liquid discharge head according to claim 1, wherein the grooves constituting the first and second restricting bodies are arranged on one main surface of one of the plurality of plates. . When the flow path member is viewed in plan view,
The width of the opening in front of the first inflow hole on the side of the first inflow hole of the first main body is larger than the width of the opening in the center of the first main body.
5. The width of the opening on the side of the second inflow hole of the second squeezing main body before reaching the second inflow hole is larger than the width of the opening at the center of the second squeezing main body. The liquid discharge head according to any one of the above.   The opening of the first inflow hole and the opening of the second inflow hole in the common flow path are the first of the plates in which holes or grooves constituting the common flow path are arranged. The liquid discharge according to any one of claims 1 to 5, wherein an opening is made in a groove disposed on one main surface of the plate disposed at a position close to the second main body and the second main body. head. When the flow path member is viewed in plan view,
More than half of the length of the first squeezing body is sandwiched between two adjacent second squeezing bodies,
The liquid ejection head according to claim 1, wherein at least half of the length of the second restriction body is sandwiched between two adjacent first restriction bodies. When the flow path member is viewed in plan view,
2/3 or more of the length of the first squeezing body is sandwiched between two adjacent second squeezes,
The liquid ejection head according to claim 7, wherein at least 2/3 of the length of the second squeezing main body is sandwiched between two adjacent first squeezes. The flow path member is configured such that the plurality of plates are bonded to each other with an adhesive,
When the flow path member is viewed in plan view,
A plurality of second partial flow passages respectively connecting the plurality of pressurization chambers belonging to the second pressurization chamber row and the plurality of discharge holes are provided on one side in the other direction of the common flow passage. Are arranged in the one direction,
Openings of the plurality of second partial flow paths are arranged in the one direction on at least one main surface of the plate on which holes or grooves constituting the first restriction body are arranged, and the plurality The first inflow hole opening is disposed in the one direction, and the adhesive extending in the one direction is between the plurality of second partial flow path openings and the plurality of first inflow hole openings. A first relief groove is arranged,
The liquid discharge head according to claim 1, wherein the first relief groove is disposed so as not to overlap the common flow path. The flow path member is configured such that the plurality of plates are bonded to each other with an adhesive,
When the flow path member is viewed in plan view,
A plurality of first partial passages respectively connecting the plurality of pressurization chambers belonging to the first pressurization chamber row and the plurality of discharge holes are provided on the other side in the other direction of the common flow passage. Are arranged in the one direction,
In at least one main surface of the plate where the holes or grooves constituting the second squeezing body are arranged, the openings of the plurality of first partial flow paths are arranged in the first direction, The openings of the plurality of second inflow holes are arranged in the one direction, and the bonding extends in the one direction between the openings of the plurality of first partial flow paths and the openings of the plurality of second inflow holes. A second escape groove for the agent is arranged,
10. The liquid ejection head according to claim 1, wherein the second escape groove is disposed so as not to overlap the common flow path. The flow path member is configured such that the plurality of plates are bonded to each other with an adhesive,
When the flow path member is viewed in plan view,
Of the first and second squeezing main bodies, an adhesive relief groove is arranged on the outer side of the squeezing main body arranged at the extreme end in the one direction so that the squeezing main body extends. The liquid discharge head according to claim 1.   The liquid ejection head according to claim 11, wherein a plurality of the escape grooves are arranged. A liquid discharge head according to any one of claims 1 to 12,
A transport unit for transporting a recording medium to the liquid discharge head;
And a control unit that controls the liquid discharge head.

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